A thermotropic copoly(amide ester) exhibiting a nematic mesophase within the range of 240-360 degreesC was prepared by the solution copolycondensation of p-aminobenzoic acid (40-70 mol %) and m-hydroxybenzoic acid with diphenyl chlorophosphate in pyridine in the presence of LiCl. For control of the sequence distribution of p-aminobenzoic acid, the amount of LiCl and the dropwise addition of the phosphate were examined. The transition temperatures (from a solid phase to a nematic mesophase) of the resultant copolymers were affected by the period of addition and the amounts of the aminobenzoic acid and LiCl and were investigated in terms of the distributions of the monomers determined by H-1 NMR.